How to Grow Boxwood in Oklahoma

Select an area that's sheltered from strong winds. It should receive partial to full sunlight.

Test the soil with a soil pH testing kit. The soil should have a pH between 6.5 and 7.5. If it's too acidic, add dolomitic lime at a rate of 2.5 pounds for every 100 square feet in loamy soil to raise the pH by 1.5 points. For clay soil, use 3.5 pounds. For sandy soil, use 2 pounds of lime. Mix the lime into the top 6 inches of the soil with a tiller. It takes at least a month for the lime to take effect, so apply it as early as possible. Test the soil and reapply more lime if needed.

Prepare the soil before by tilling and aerating it. The soil should have excellent drainage. If the soil is heavy clay, mix 3 inches of pine bark mulch into the top 6 inches of the soil.

Dig a hole with a shovel just deep enough to accommodate the root ball. Place the boxwood in the hole and pack down the soil around it. The top one-eighth of the root ball should stick up above the soil because boxwood is a very shallow-rooted plant. Space boxwood shrubs at least 3 feet apart.

Apply 2 to 3 inches of wood chip or pine straw mulch around the base of the boxwood shrub. Keep the the mulch at least 3 inches away from the main trunk. Replenish the mulch annually.

Water the boxwood shrub regularly and deeply until it's fully established. Water when the soil feels dry at a depth of 1 inch. After the first growing season, water only during hot, dry periods when there is less than 1 inch of rain per week.

Trim off any brown or dead tips with sharp pruning shears during the early to late spring. If the boxwood becomes overgrown, trim back the tips of stems and dispose of them. Don't cut more than one-quarter of the shrub each year.

Thin dense established boxwood in late spring to encourage new growth and prevent fungal diseases. Reach into the shrub about 6 inches and cut off stems with sharp pruning shears using quick, clean cuts. Work around the shrub, snipping off stems of dense growth to create open space inside. Prune about 10 percent of the shrub and dispose of the cuttings. This shouldn't change the look of the boxwood, but will improve air circulation.

Fertilize boxwood in the late spring of the second growing season, just before new growth begins. Use 1 1/2 cups of 10-10-10 granulated slow-release fertilizer per 100 square feet. Spread it evenly around the boxwood shrubs, at least 6 inches from the main trunk. Water the fertilizer into the soil.

Spray boxwood shrubs thoroughly with insecticidal soap weekly if you notice mites, scale, nematodes, caterpillars or leaf miners. Stop spraying when the pests are gone.